1. Technical Field
The present invention relates to video delivery over a network, and in particular, to a resource management framework for adaptive video delivery over cellular networks.
2. Description of the Related Art
Smartphones, tablets and high-speed mobile services are contributing to an explosion in data traffic on cellular networks. Scarcity in the wireless spectrum adds to the problems of supporting non-elastic traffic, which include video, leading to degradation in quality of experience (QoE) for users. In this regard, dynamically adaptive streaming is gaining popularity for streaming video over cellular networks. Adaptive streaming is a technique of video streaming over the hypertext transfer protocol (HTTP) where multiple versions of the source video are pre-encoded at different bit-rates at the video server.
Recently, video has spurred a mobile internet traffic explosion. However, the wireless network speeds are not increasing at the same rate, thereby often leading to congestion at the wireless access links. To overcome this challenge, industry is adopting hypertext transfer protocol (HTTP)-based adaptive video streaming technology that enables the dynamic adaptation of the video bit-rate to match the changing network conditions. Adaptive streaming leverages the underlying transmission control protocol (TCP) transport to estimate the available capacity for data flow, and to choose the most appropriate video bit-rate based on the estimated capacity. However, recent measurement studies have found problems in fairness, stability, and efficiency when multiple adaptive video flows compete for bandwidth on a common wired or wireless link. The problems manifest mainly as (a) instability implying unnecessary switching of the video bit-rate for a particular flow, (b) unfairness in the allocation of bit-rates among the competing flows and (c) potential under-utilization of the link.